Imagine that you are at the top of a ski slope, about to make a run. It’s a challenging slope, black diamond—steep and narrow, lots of trees. Plus it’s windy, and there’s that treacherous drop-off on the right. You’re an inexperienced skier, not a novice but not at all confident that you belong in such extreme terrain. Your heart is pounding and your gut is tight.

Now imagine that you’re on top of the very same slope, but you are a skilled downhill racer, an Olympic contender. You’re sure you know how to attack this slope—you’ve done it many times before—but even so, your heart is pounding and butterflies are fluttering in your gut.

Both of these hypothetical skiers are under stress, and feeling the arousal that comes with stress. But one is experiencing good stress, the other bad stress. They are both looking at the same slope, but one sees it as a threat, the other as a challenge. The expert knows that his skills are more than sufficient for the situation. The nervous learner has no such confidence.

Psychological scientists are interested in this contrast, as are health professionals. We tend to think of stress as negative, and arousal as harmful, and indeed we spend lots of time and money—on vacations, fitness clubs, bar tabs—trying to minimize stress. But is it possible that stress is not all that bad, that in fact it may be tonic at times?

The key is how we think about stress and arousal. Those two skiers are in fact experiencing different bodily changes. Though both are feeling activation of the sympathetic nervous system, the fearful skier is feeling constriction of the vessels, which makes the heart work harder. The expert is actually experiencing more sympathetic arousal as he contemplates the challenge ahead, but the blood vessels are dilating, increasing cardiac efficiency. But they don’t know or care what’s going on inside them. They both simply feel edgy and aroused.

What if the learner’s fear could be construed as a positive challenge? What a skier—or anyone—could be made to believe that the pounding and fluttering were actually a resource, tools for enhanced performance? That’s the question that University of Rochester scientist Jeremy Jamieson wanted to explore in the laboratory. Working with UCSF’s Wendy Berry Mendes and Harvard’s Matthew Nock, he has run a series of experiments to see if bad stress can be transformed into good stress in the mind.

Here’s an example. The researchers took physiological measurements on a group of volunteers, who were told that they would have to make a public speech—a stressful prospect for most people. Just prior to this event, some were instructed about the value of human stress response in high-level performance. They were encouraged to interpret any signs of arousal as a positive thing, a tool that would aid them in making a confident speech. The others were told to ignore their stress arousal, or they were told nothing at all.

The findings were clear. During the speech, those instructed in reappraisal were much more like the Olympian skier, showing what Jamieson calls “physiological toughness”: They experienced less blood vessel constriction and more cardiac output, as if they were attacking the slope. What’s more, immediately after the speech, these volunteers were less vigilant. In other words, they felt confident, not threatened.

Think about this. It wasn’t an elaborate intervention. They were merely encouraged to reappraise their gut feelings. The scientists decided to test this simple idea again, in the context a high-stress real-life event: a high-stakes examination. They recruited students who were already preparing to take the Graduate Record Examination (GRE), guaranteeing that their performance was genuinely important to them. The students came into the lab to take a practice version of the exam. As before, only some were told that their nervous stomachs and pumping hearts were known to improve, not worsen, performance. Right before the test, all the students gave saliva samples for analysis.

Those who were taught to reappraise their arousal—to see it as a benefit—had higher levels of alpha amylase, an indicator of nervous system arousal, and they performed better on the practice GRE. But here’s the really interesting part: One to three months later, when they took the actual GRE under regular testing conditions, these students had higher math scores than the controls. And they also reported that their test-day arousal had helped them with the exam. This brief and simple intervention had sustained effects on both stress appraisal and test performance.

These are just a couple examples on ongoing research that the Jamieson and his colleagues will describe in a forthcoming issue of the journal Current Directions in Psychological Science. The findings may change the way that clinicians think about acute, everyday stress and a variety of ills. Much valuable work has shown that we can regulate our emotions and mitigate our stress arousal—through mindfulness mediation, for example. But there are many times when it’s impossible, or inadvisable, to dampen the body’s arousal signals. Reappraisal may offer an additional tool to cope with bodily stress in an adaptive way.

Wray Herbert’s book, On Second Thought, is about irrational thinking and decision making. Excerpts from his two blogs—“We’re Only Human” and “Full Frontal Psychology”—appear regularly in The Huffington Post and in Scientific American Mind.